Move full-res sponsor images into Resources.

Resources directory houses full-resolution versions.
Put optimized sponsor images in Images directory.

Optimized for size.  Max-width is 384px which is grid-5 width.
Add sponsor section to home page.

Sponsors replaces the Logo Contest section.
Style sponsors.

More generally, adapt paragraph top and bottom margins to give priority
to headings immediately preceding and following.
Input 2013 logistics copy.

Tournament details courtesy TD.
Fix medium-smartphone spacing.

Force grid_12 (ie 100%) width elements to be 100% width for all screens.